KAMPALA, Uganda - Forest Whitaker is hotly tipped to win an Oscar on Sunday for his portrayal of Idi Amin in the movie "The Last King of Scotland.''

But for the former tyrant's son Jaffar, the performance failed to capture the tall, powerful man he still describes as his "Big Daddy.'' The Amin family has shunned the media for over two decades, but now that the film has put the Ugandan dictator back into the spotlight, his son wants to set the record straight.

"Dad is the only person that has ever been accused and sentenced, incarcerated by opinion, without it ever reaching any courthouse,'' Jaffar Amin said in an interview, calling for a truth and reconciliation committee to investigate that dark period in Uganda's history.

Jaffar Amin, a 40-year-old father of five with broad shoulders, confident demeanour and a rich baritone voice, bears a striking resemblance to his father.

Though he doesn't deny the atrocities attributed to his father during his reign of terror, he says the film will compound many of the negative images on which he is now trying to shed some light.

He acknowledges he faces a difficult battle trying to humanize Idi Amin.

"Dad's image cannot be changed,'' he sighed. "If I bring an understanding, it will be very little because he's in a compartment and getting him out of there will take a thousand years. But I believe my father would take it on the chin whatever they say about him.''

Jaffar Amin has broken the family's vow of silence and is writing a book to counter his father's reputation as a brutal buffoon and cruel eccentric.

Rights groups estimate that up to 500,000 people disappeared under Amin's eight year regime. His secret police force was notorious for torturing and killing Ugandans they believed to be political opponents.

"I don't want to fight what has been written, but I want to show another side. I want to show a parent, I want to show my father,'' he said.

He is the tenth of Amin's 40 official children by seven official wives. "Father had quite an appetite for women,'' he said simply. "It's very African actually.''

At six foot one he is also the shortest of Amin's sons.

"My father was six foot four but most of his male children towered over him. He used to joke that we would make a great basketball team,'' Jaffar recalled with a smile.

The "Last King of Scotland'' premiered in Uganda last week and goes on general release Friday. Oscar-nominated Forest Whitaker, James McAvoy and director Kevin MacDonald attended the grand-opening along with Uganda's President Yoweri Museveni.

None of the Amin family attended the premiere but Jaffar has since watched a DVD of the film.

"A lot of the mannerisms were right. But the problem was the walk -- Forest didn't get that. My father strides and his hands would go like a paddle because of his wide shoulders. Whitaker is knock-kneed -- my father was bow-legged.''

Jaffar Amin's main complaint about "The Last King of Scotland,'' however, was the portrayal of Kay Amin -- the dictator's forth wife -- a woman he lived with at one of Amin's official state residences and whom he describes as a second mother to him.

In the film, Kay is killed for having an affair with Dr. Garrigan, Amin's physician, who Jaffar Amin also met. Her body is mutilated in the morgue -- her arms stitched to where her legs should be and vice versa.

"The most painful part for me is degrading the character of one of our blessed mothers,'' he said visibly distressed. "She had a tragic death and they turned her into what she wasn't, she was a decent lady. She wouldn't have an extramarital affair the way it's claimed.''

But he is vague about the circumstances of her death, describing it as a "sensitive issue.'' He adds that Kay's father cleared Idi Amin of any wrongdoing in his daughter's death.

The Amin family fled Uganda when Idi Amin was ousted by Tanzanian-backed Ugandan rebels in 1979. They lived in exile in Saudi Arabia, where many of the family remain to this day.

The family was given a huge monthly allowance that allowed them to live an opulent lifestyle. In return, Amin was asked to stay out of politics and remain silent. It was a promise he kept up his death in August 2003 at age 78.

Jaffar Amin, an animated, open man, punctuates his conversation with impersonations of his father and shows pictures of his own five children, one of whom he has named Idi Amin and describes as a "carbon-copy'' of his notorious grandfather.

"I point at a picture and I say to my children `that's your grandfather. He used to be the leader of this country,' '' he said.

Jaffar Amin returned to Uganda in 1990 and worked for a courier company. He now does voice overs for advertisements.

"I'd ask dad, what happened? He'd look at me and say `people fought me, I fought them but I never killed innocent people. God will be the one to judge me.' ''